Patrick "Dutchy" Holland, who became Ireland's most-infamous murderer by being fingered in the slaying of crusading crime journalist Veronica Guerin, has died at 70 of natural causes.

A Dublin native and former U.S. Marine, Holland was a career criminal and a drug dealer. His rap sheet rolled back a long way -- back to the 1960s.

He later joined a big-time drug gang led by John Gilligan. Police probing the murder of Veronica Guerin in June 1996 learned from gang snitches Holland was her killer. He went on the lam and fled Ireland, but returned to Dublin a year later.

During a trial on earlier drug charges, Police Officer Marion Cusack testified that she arrested Holland on suspicion of having a firearm at the location where Guerin was shot.

Cusack said: “I had formed the opinion that Patrick Holland was the man who shot dead Veronica Guerin.”

Holland was never charged with the murder, and always denied any involvement. "I haven’t killed anybody ever. There is no blood on my hands,” he famously claimed.

He was convicted of the drug charges and sentenced to 20 years in prison.